Apparatus for producing uniform printwork



March 27, 1962 CETRAN 3,026,986

APPARATUS FOR PRODUCING UNIFORM PRINTWORK Filed Sept. 6, 1960 I Fl'gJ VENTOR L C ETR AN tic of impact printing machines.

United States Patent 3,026,986 APPARATUS FOR PRODUCING UNIFORM PRINTWORK Louis Cetran, Newington, Conn., assignor to Royal Mc- Bee Corporation, Port Chester, N.Y., a corporation of New York Filed Sept. 6, 1960, Ser. No. 54,159 3 Claims. (Cl. 197--127) This invention relates generally to improved apparatus for producing uniform printwork; more particularly it relates to improved apparatus of the type described having means for controlling the path of travel about the platen of a business machine of records positioned therein to receive printwork, and specifically it relates to improved apparatus of the type described wherein said means is designed to control the path of travel of an original record or hectograph ribbons and/or ledger sheets positioned to receive impressions through the original record such as a check, card or sheet.

The printwork produced by present day business machines, while adequate, does not measure up to the high quality copy produced by press printing processes due to the nonuniform density of the material transferred to a record, whether from inked ribbons, hectograph ribbons or carbon sheets. This nonuniform disposition of transfer material is attributable to the mechanics characteris- Expedients toward improving the quality of printwork have involved the choice of materials of which the platen is fabricated, its diameter, and the design of the curvature of the type characters to name a few. While each has contributed to improved quality, nonuniform disposition of transfer material is still a problem.

In accordance with the present invention it has been found that by providing a small gap between the record which is to receive printing, and the platen, the printwork produced is of extremely uniform density. The gap is accomplished by a device which produces an open loop between the pressure roller in contact with the platen downstream of the printing point and a point upstream of the printing point.

An object of the invention is in the provision of apparatus for improving the quality of printwork of business machines.

Another object of the invention is to provide apparatus whereby a gap is formed between the record which is to receive or transfer printwork, and the platen.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a front view of a business machine platen assembly with the structure of the invention attached thereto;

FIGURE 2 is a cross sectional view of a business machine platen and paper feed rolls with apparatus in accordance with the invention associated therewith supporting an original record; and

FIGURE 3 is a view similar to FIGURE 2 showing a machine supporting a record which may be a hectograph ribbon or a ledger sheet. If the record is a hectograph ribbon it is adapted to deposit hectograph material on the rear of a master card disposed in a card trough in front of the printing point; and when it is a ledger sheet it is adapted to receive printwork via a carbon paper associated therewith through type impressions on a bill sheet.

Referring now to the drawings wherein is shown a single station of a business machine.

preferred embodiment of the invention, and wherein like reference numerals designate like or corresponding reference numerals throughout the several views thereof, there is shown in FIGURES 1 and 2 a platen 11 which, as understood in the art is supported for rotation on a carriage movable transversely with respect to the printing Associated with the platen is a paper bail 12 mounted on the carriage and spring urged toward the platen whereby pressure rollers 13 rotatably mounted thereon, frictionally engage the platen roll. As is understood in the art the paper bail 12 is movable to a position spaced from the platen to enable insertion and alignment of a record. The above constru-ction is conventional.

In accordance with the invention there is provided a thin rod 14 which extends across the machine forwardly of the paper bail. The extremities of the rod 14 extend rearwardly and are preferably rotatably mounted on the paper bail at the ends thereof by any suitable means as by forming the ends around the bail as shown in FIGURE 2. As shown in FIGURE 2 a record designated R is threaded around the platen, around the transverse rod 14 and between the pressure rollers 13 and the platen thereby causing a loop in the record R which produces a gap 15 (exaggerated in the drawings) between the record and the platen in front of the printing line. When the platen is indexed, the record R is pulled by the frictional engagement of the pressure rolls 13 and the platen, as is understood; the rod itself being maintained by the geometry of the parts and in turn maintaining the predetermined loop in the record during indexing movement. As heretofore stated-the spacing or gap 15 between the platen and record in front of the printing line acts to produce a transfer of ink from the typewriter ribbon 16 (FIGURE 3) to the front side of the record in response to the impact of a type bar 17, which is of very uniform density.

FIGURE 3 shows the principle of the invention applied to a hectographing or accounting operation. In a hectographing application a master card 18 is supported in a card trough, as disclosed and claimed in copending application Serial No. 701,749, filed December 10, 1957, now Patent No. 2,978,087, in front of a hectograph ribbon R whereby hectograph material is transferred to the back of the master card. Here too extremely uniform density transfers have been achieved as a result of the gap between platen and hectograph ribbon at the printing line.

In an accounting operation a tally or ledger-carbon sheet, represented by reference numeral R" is fed from a roll (not shown) around the platen and spaced from the printing line by a gap 15 in accordance with the invention. Here a bill sheet or customers monthly account sheet represented by reference numeral 18' is threaded into the machine below the conventional paper pan 21, and in front of the ledger sheet R". In such an application both the bill and ledger sheets exhibited extremely uniform density printwork as a result of the spacing between platen and records at the printing line.

The gap spacing requisite for the improvement of printwork is empirically determined for each application. Experience shows that gap spacings within the range of from .030 to .060" will give the extremely uniform density transfers synonymous with high quality printwork. Obviously the optimum gap spacings can be accomplished by adjusting the reach of the bar 14 forwardly or rearwardly, upwardly or downwardly by bending or other suitable means.

It should be understood that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen q) for the purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

The invention claimed is:

1. In a typewriter having a movable carriage, a platen rotatably mounted on said carriage, and a paper bail mounted on said carriage having pressure rollers mounted thereon adapted to frictionally engage said platen downstream of the typewriter printing line whereby record media wound about said platen and frictionally engaged between said platen and pressure rollers may be indexed when said platen is rotated, said record media including transfer sheets, means mounted on said paper bail extending therefrom forwardly of the printing plane of said typewriter for producing a loop in said record media between a line upstream of said printing line and said pressure rollers whereby said record media will be spaced a predetermined distance from said platen opposite said printing line.

2 In a business machine having a movable carriage, a platen rotatably mounted on said carriage, and a paper bail mounted on said carriage downstream of the printing line of said machine, said paper bail having pressure rollers thereon adapted to frictionally engage said platen whereby record media wound about said platen and frictionally engaged between said platen and pressure rollers may be indexed when said platen is rotated, said record media including transfer sheets and sheets adapted to receive material from said transfer sheets, the improvement comprising carriage mounted means positioned between said printing line and said pressure rollers forwardly 4 of the printing plane of said machine for creating a loop in said record media whereby said record media will be spaced a predetermined distance from said platen opposite said printing line.

3. In a typewriter having a movable carriage, a platen rotatably mounted on said carriage, and pressure rollers mounted on said carriage downstream of the printing line of said typewriter adapted to be frictionally driven by said platen when said platen is rotated whereby record media wound about said platen and between said platen and pressure rollers may be indexed, said record media comprising a hectograph sheet adjacent said platen and a copy sheet next adjacent said platen, said hectograph sheet being adapted to transfer copy to the rear side of said copy sheet when copy is typed on the front side of said copy sheet, and means mounted on said carriage between said printing line and said pressure rollers extending forwardly of the typewriter printing plane for creating a loop in said record media between a line below said printing line and said pressure rollers whereby said record media is spaced a predetermined distance from said platen opposite said printing line.

References Cited in the file of this patent UNITED STATES PATENTS 1,737,337 Sanders Nov. 26, 1929 2,123,280 Hart July 12, 1938 2,32Q,394 Ratchford et al June 1, 1943 

